Includes addition of 'calendar' attribute to time variable in netcdf

base_time is epoch seconds
time_offset is seconds from base_time
time is hours from midnight

Includes fixes and clean up for specifying multiple files versus
a single input file.

Properly calculate wind gust
Properly assign QC flags
Tons of style changes and better performant array operations

If dewpoint is missing from netcdf files, the script uses rel_hum and
air_temp data to recreate dewpoint data

--daily was calculating min and max of temperature and dewpoint
plot wrong by not considering dewpoint at all - that has now
been fixed

Title was a bit too big
changed it to 13

creates aoss tower quicklooks

1 min files now have datastream nc-1d-1m
monthly files now have datastream nc-1mo-1m